//
// Created by hsj on 2024-1-12.
// 多播基于UDP;多播组是D类IP地址( 224.0.0.0~ -239.255.255.255 )
// D类地址224.x.x.x~239.x.x.x
// 编译:  gcc multicast_send_win.c -LH:\mingw\mingw64\x86_64-w64-mingw32\lib -lws2_32 -o multicast_send_win
#include <sys/time.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <ctype.h>
#include <fcntl.h>

#ifdef WIN32
//windows minGW64
//inet_pton函数：_WIN32_WINNT
#ifdef _WIN32_WINNT
#undef _WIN32_WINNT
#endif
#define _WIN32_WINNT 0x0600
#include <winsock2.h>
#include <ws2tcpip.h>
//#pragma comment(lib,"ws2_32.lib")
#else
//linux  gcc
#include <arpa/inet.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/select.h>
#endif
#define TTL 64
#define BUF_SIZE 30
void ErrorHandling(char *buf);
int main(int argc,char *argv[]){
    WSADATA wsaData;
    SOCKET hSendSock;
    SOCKADDR_IN mulAdr;
    int timeLive=TTL;
    FILE *fp;
    char buf[BUF_SIZE] ;
    char ip[]="224.1.1.2";
    char port[]="1188";

    if(WSAStartup(MAKEWORD(2, 2), &wsaData)!=0)
        ErrorHandling( "WSAStartup() error!");

    hSendSock=socket(PF_INET, SOCK_DGRAM, 0);
    memset(&mulAdr, 0, sizeof(mulAdr));
    mulAdr.sin_family=AF_INET;
    mulAdr.sin_addr.s_addr=inet_addr(/*argv[1]*/ip);
    mulAdr.sin_port=htons(atoi(/*argv[2]*/port));

    setsockopt(hSendSock, IPPROTO_IP,
            IP_MULTICAST_TTL, (void* )&timeLive, sizeof(timeLive));

    if((fp=fopen( "news.txt", "r"))==NULL)
        ErrorHandling("fopen() error");

    while(!feof(fp))
    {
        fgets(buf, BUF_SIZE, fp);
        printf("%s\n",buf);
        sendto(hSendSock, buf, strlen(buf),0, (SOCKADDR* )&mulAdr, sizeof(mulAdr));
        Sleep(2000);//sleep 2 sec
    }
    fclose(fp);
    closesocket(hSendSock);
    WSACleanup();

    return EXIT_SUCCESS;
}

void ErrorHandling( char *message){
    fputs (message, stderr);
    fputc('\n', stderr);
    exit(1);
}

